Conversion of high molecular weight petroleum feeds to more valuable products by catalytic processes such as hydrocracking is important to petroleum processes. Hydrocracking of relatively high boiling point hydrocarbons, such as atmospheric and vacuum gasoil cuts from crude oil, is generally done to form a converted product having a more useful boiling point, so that it can be predominantly used in any one or more of a variety of fuels, such as naphtha (motor gasoline), jet fuel, kerosene, diesel, and the like. Usually, however, particularly when targeting distillate product fractions, the hydrocracking reaction is run at relatively low severity or relatively low hydrocracking conversion, so that the higher boiling point hydrocarbons are not cracked too much, as higher conversions typically generate increasing quantities of material boiling in the ranges below naphtha, which low boiling material tends not to be as commercially useful as the fuel compositions. However, running at these lower temperatures (severities), tend to reduce the overall product conversions. While maintaining a better selectivity for distillates, overall conversion, as well as overall distillate production can be significantly decreased.
Additionally, with hydrocracking catalysts of the art, low overall process conversions leave behind higher quantities of higher boiling range hydrocarbons that cannot be used as fuels and that tend to have poor properties for use in such applications as lubricants, without further significant processing steps. Such steps can add complexity and cost to dealing with such otherwise unusable higher boiling range hydrocarbons, and options such as coking for such hydrocarbons can offer relatively marginal return on investment.
There are many patent publications that disclose hydrocracking processes for attaining good fuels properties, and also for attaining good lubes properties. A non-exclusive list of such publications includes, for example, U.S. Pat. Nos. 5,282,958, 5,953,414, 6,413,412, 6,652,735, 6,723,889, 7,077,948, 7,261,805, and 7,300,900, U.S. Patent Application Publication Nos. 2003/0085154, 2004/0050753, 2004/0118744, and 2009/0166256, and European Patent Nos. 0 649 896 and 0 743 351.
Nevertheless, it would be desirable to discover improved hydrocracking catalysts compositions and associated hydrocracking processes in Which a higher boiling point hydrocarbon, such as a vacuum gasoil, can be hydroprocessed (hydrocracked) to allow beneficial use of the converted portion in fuels compositions while increasing both the conversion of the 700° F.+ boiling point materials in the hydrocracker feedstream, while increasing the amount that is selectively cracked into distillate range materials (i.e., the “400-700° F. Yield”).